121- 88 = 33 miles traversed in 30 minutes.
d = r*t
33 = r* (.5 hr)
Solve for r.
Average speed will be in miles per hour.
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Answer:
3
Step-by-step explanation:
Answer:
a) 820
b)450
c) -540
d) -294
e) 1440
f) 1425
Step-by-step explanation:
a) it is an arithmetic progression with ratio=4
a1=3,
a2=3+r=3+4=7.....
a20=a1+19r
so a20=3+19*4=3+76=79
S=(a1+an)*n/2 where n=20
so S=(3+79)*20/2=820
b) a15=a1+14*r=2+14*4=2+56=58
S=(a1+a15)*15/2=(2+58)*15/2=60*15/2=30*15=450
It is the same formula for all the exercises
S=(a1+an)*n/2 , where n is the number of terms
c) a40=30+39*(-3)=30-87=-57
So S=(30-57)*40/2=-540
d) a14=5+13*(-4)=5-52=-47
S=(5-47)*14/2=-42*14/2=-42*7=-294
e) it is 5+7+9+......+75
nr of terms = (an-a1) :r+1=(75-5):2+1=36
S=(5+75)*36/2=36*40=1440
f) ratio=7-4=3
the same formula for n= (91-4):3+1=87:3+1=29+1=30
S=(4+91)*30/2=95*30/2=2850/2=1425
Answer:
<h3>1</h3>
Step-by-step explanation:
The nth term of an exponential sequence is expressed as ar^n-1
The nth term of a linear sequence is expressed as Tn = a + (n-1)d
a is the first term
r is the common ratio
d is the common difference
n is the number of terms
Let the three consecutive terms of an exponential sequence be a/r, a and ar
second term of a linear sequence = a +d
third term of a linear sequence = a + 2d
sixth term of a linear sequence = a + 5d
Now if the three consecutive terms of an exponential sequence are the second third and sixth terms of a linear sequence, this is expressed as;
a/r = a + d ..... 1
a = a + 2d ..... 2
ar = a+ 5d .... 3
From 2: a = a + 2d
a-a= 2d
0 = 2d
d = 0/2
d = 0
Substitute d = 0 into equation 1:
From 1: a/r = a + d
a/r = a+0
a/r = a
Cross multiply
a = ar
a/a = r
1 = r
Rearrange
r = 1
<em>Hence the common ratio of the exponential sequence is 1</em>
